Cylinder for internal-combustion engines



. APPLICATION FILED AUG-2|, I918.

:fi-p plllo v E. SCHNEIDER CYLINDER FOR INTERNAL COMBUSTION ENGINES.

mm June 192m 2 SHEETS-SHEET I- V f7 M //y /4 3 1 WW a all E. SCHNEIDER. CYLINDER FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED AUG.2I| I9I8.

Patented June 8, LOZO.

2 SHEETS-SHEET 2 EUGENE SCHNEIDER, 0F PARIS, FRAN CE, ASSIGNOR TO SCHNEIDER & CIE., 0F PARIS, FRANCE, A LIMITED J OINT-STOCK COMPANY OF FRANCE.

CYLINDER FOR INTERNAL-COMBUSTION ENGINES.

Specification of Letters Patent.

Patented June 8, 1920.

Application filed August 21, 1918. Serial No. 250,860.

To all whom it may concern:

Be it known that I, EUGENE SCHNEIDER, a citizen of the French Republic, and a resident of 42 Rue dAnjou, Paris, France, have invented new and useful Improvements in Cylinders for Internal Combustion Engines, which invention is fully set forth in the following specification.

This invention relates to engine cylinders, particularly of the type employed in twocycle internal combustion engines.

It is customary in two-cycle internal combustion engines to effect the exhaust of the gases of combustion through ports which are circumferentially arranged in the walls of the cylinders and are uncovered by the pistons during a portion of their outward or working stroke.

When the scavenging air is admitted through valves located in the combustion chamber, or the cylinder head, the exhaust ports are disposed in a row around the whole interior circumference of the cylinder. If, on the other hand, the scavenging air is admitted at the lower portion of the cylinder,

- the exhaust ports are-arranged in a semlcircle and the admission ports in a semicircle opposite thereto. In both cases, the ports extend around the whole interior circumference of the cylinder.

Such arrangements have serious disadvantages where the piston is directly connected I to the end of the connecting rod, A piston thus connected receives the reactions of the end of the connecting rod during the working stroke corresponding to the combustion and expansion period, which reactions are particularly powerful and, being transmitted by the piston to the cylinder wall which is then serving as a guide, cause heavy pressure by the piston on said wall. Owing to the ports whereby the bearing surface of the piston on the'cylindervis considerably reduced, the pressure per unit' area on the cylinder wall between the ports is too great to permit of the engine working with insured safety and without too rapid wear.

The present invention has for its object to obviate such drawbacks and, to this end, the ports, instead of being arranged all around the interior circumference of the cylinder, are disposed only part-way around the same and in a manner not to adversely afi'ect the zone wherein the piston presses on the cylinder wall under the reactions of the end of the connecting rod during the working stroke. A suitable bearing surface is thus provided.

The invention is capable of receiving a variety of mechanical expressions two of which are shown on the accompanying drawing, but it is to be expressly understood that the drawing is for purposes of illustration only and is not to be construed as a the exhaust only is eflected in the lower part of the cylinder, scavenging air being admitted at the upper part.

In the drawing, 1 denotes the cylinder, 2 its liner, fixed therein in any suitable manner, 3 the exhaust ports, and 4 the exhaust outlet passage.

The ports 3 are shown as arranged around only part of the circumference of the cylinder in a manner to preserve, for the bearing of the'piston, a large unapertured surface, to wit, the portion mn-- represented by hatched lines in Fig. 1.

In Fig. 3 is shown the piston and its associated crank in a position that it may have during the working stroke. 1

The working pressure F can be resolved into a component F along the connecting rod and a component F normal to the cylinder. The latter component, which represents a force arising from the reaction of the connecting rod, is transmitted to the piston, and bythe latter t9 the large bearing surface 'm,- n on the. cylinder wall.

. his arrangement permits, moreover, of oil feed ducts for securing efiective lubrication being suitably located in the part m-n without the oil being able to find, its way to the exhaust ports. 5 and 6 represent such ducts, while 7 is a duct for the supply thereto of the oil.

Fig. at represents the application of the invention to a cylinder wherein the scavenging is effected from the lower part of the cylinder. In this form, 8 represents orifices for the admission of the scavenging air and 9 is a conduit for the supply thereof. 10 represents the exhaust ports and 11 the exhaust outlet passage. The portion m-n, as in the previous example, is the region wherein the pressure of the piston on the cylinder wall, arising from the reactions of the connecting rod, is borne.

While the illustrated embodiments have been described with considerable particularity, it is to be understood that the invention is not to be restricted thereto as the same is capable of receiving a variety of mechanical expressions. Reference is to be had to the claims hereto appended for a definition of the limits of the invention.

What is claimed is 1. A cylinder for a two-cycle internal combustion engine provided with a circumferential series of ports including exhaust ports, said series of ports extending around only a portion of the internal circumference of the cylinder and leaving a relatively large unapertured surface for the bearing of the piston in that portion of the cylinder wall which receives the pressure arising from the reaction of' the connecting rod during the working stroke.

2. A cylinder for a two-cycle internal combustion engine provided with a circumferential series of ports including exhaust ports, said series of ports extending around only a portion of the internal circumference of the cylinder and leaving a relatively large unapertured surface for the bearing of the piston in that portion of the cylinder wall which receives the pressure arising fromthe reaction of the connecting rod during the working stroke, and oil-feed ducts arranged in said unapertured portion of the cylinder wall.

3. The combination in a two-cycle internal combustion engine, of a cylinder pro vided with a circumferential series of ports including exhaust ports a piston working in said cylinder, and a connecting rod directly connected to said piston, said series of ports extending around only a portion of the internal circumference of said cylinder and leaving a relatively large unapertured surface for the bearing of the piston in that portion of the cylinder wall which receives the pressure arising from the reaction of the connecting rod during the working stroke.

In testimony whereof I have signed this specification. I

EUGENE SCHNEIDER.

Witnesses i ANDRE MosTIoKER JOHN F. SIMoNs' 

